bindings: Ignores the last undefined arguments when counting the args.

third_party/WebKit/Source/bindings/scripts/v8_methods.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 102 matching lines @@
     is_post_message = 'PostMessage' in extended_attributes
     if is_post_message:
         includes.add('bindings/core/v8/SerializedScriptValueFactory.h')
         includes.add('core/dom/DOMArrayBuffer.h')
         includes.add('core/dom/MessagePort.h')
         includes.add('core/frame/ImageBitmap.h')
 
     if 'LenientThis' in extended_attributes:
         raise Exception('[LenientThis] is not supported for operations.')
 
+    argument_contexts = [
+        argument_context(interface, method, argument, index, is_visible=is_visible)
+        for index, argument in enumerate(arguments)]
+
     return {
         'activity_logging_world_list': v8_utilities.activity_logging_world_list(method),  # [ActivityLogging]
-        'arguments': [argument_context(interface, method, argument, index, is_visible=is_visible)
-                      for index, argument in enumerate(arguments)],
+        'arguments': argument_contexts,
         'argument_declarations_for_private_script':
             argument_declarations_for_private_script(interface, method),
         'conditional_string': v8_utilities.conditional_string(method),
         'cpp_type': (v8_types.cpp_template_type('Nullable', idl_type.cpp_type)
                      if idl_type.is_explicit_nullable else idl_type.cpp_type),
         'cpp_value': this_cpp_value,
         'cpp_type_initializer': idl_type.cpp_type_initializer,
         'custom_registration_extended_attributes':
             CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES.intersection(
                 extended_attributes.iterkeys()),
         'deprecate_as': v8_utilities.deprecate_as(method),  # [DeprecateAs]
         'exposed_test': v8_utilities.exposed(method, interface),  # [Exposed]
         # TODO(yukishiino): Retire has_custom_registration flag.  Should be
         # replaced with V8DOMConfiguration::PropertyLocationConfiguration.
         'has_custom_registration':
             v8_utilities.has_extended_attribute(
                 method, CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES),
         'has_exception_state':
             is_raises_exception or
             is_check_security_for_frame or
             is_check_security_for_window or
             any(argument for argument in arguments
                 if (argument.idl_type.name == 'SerializedScriptValue' or
                     argument_conversion_needs_exception_state(method, argument))),
+        'has_optional_argument_without_default_value':
+            any(True for argument_context in argument_contexts

[bashi, 2015/11/26 23:37:18]

Can we have a helper function for |has_optional_argument_without_default_value|
and use it in both v8_method.py and v8_interface.py?

[Yuki, 2015/11/30 06:53:23]

Done.

+                if (argument_context['is_optional'] and
+                    not argument_context['has_default'] and
+                    not argument_context['is_dictionary'] and
+                    not argument_context['is_callback_interface'])),
         'idl_type': idl_type.base_type,
         'is_call_with_execution_context': has_extended_attribute_value(method, 'CallWith', 'ExecutionContext'),
         'is_call_with_script_arguments': is_call_with_script_arguments,
         'is_call_with_script_state': is_call_with_script_state,
         'is_call_with_this_value': is_call_with_this_value,
         'is_check_security_for_frame': is_check_security_for_frame,
         'is_check_security_for_node': is_check_security_for_node,
         'is_check_security_for_window': is_check_security_for_window,
         'is_custom': 'Custom' in extended_attributes and
             not (is_custom_call_prologue or is_custom_call_epilogue),
@@ skipping 302 matching lines @@
     return method.idl_type and method.idl_type.name == 'Promise'
 
 IdlOperation.returns_promise = property(method_returns_promise)
 
 
 def argument_conversion_needs_exception_state(method, argument):
     idl_type = argument.idl_type
     return (idl_type.v8_conversion_needs_exception_state or
             argument.is_variadic or
             (method.returns_promise and idl_type.is_string_type))